Actuators are used in myriad devices and systems. For example, many vehicles including, for example, aircraft, spacecraft, watercraft, and numerous other terrestrial and non-terrestrial vehicles, include one or more actuators to effect the movement of various control surfaces or components. In many applications such as, for example, aircraft flight surface control systems, missile thrust vector control systems, and submarines, the actuators that are used may be subject to relatively severe environmental conditions, as well as relatively high magnitude shock and vibration. For these reasons, as well as to ensure system availability for mission completion, it is desirable that at least some of the actuators that may be subject to such environmental conditions exhibit suitable redundancy.
For many of the above-mentioned applications, it is becoming increasingly desirable to use electromechanical actuators (EMAs). A typical EMA includes an electric motor that, when properly energized, supplies a torque to a suitable actuation device, which in turn positions a control surface or component. For at least some of the above-mentioned applications relatively small, lightweight actuators are desired. Moreover, relatively quiet actuators, with little or insignificant acoustic signatures may also be needed.
Hence, there is a need for an EMA that exhibits little or insignificant acoustic signature. The present invention addresses at least this need.